Field of the Invention
The present invention relates to a transmission for a vehicle, the transmission having a compact structure without disconnection at any gear stage during shifting.
Description of the Related Art
An automated manual transmission can provide convenience for a driver, similar to an automatic transmission, by providing automatic shifting by means of an actuator while a vehicle is driven, and can contribute to improving fuel efficiency of a vehicle while maintaining power transmission efficiency higher than an automatic transmission.
The automated manual transmission is a device that automatically controls gears to shift by means of not a driver, but a TCU (Transmission Control Unit), using a hydraulic and pneumatic actuator in a manual transmission.
However, for an automated manual transmission based on a synchro-mesh type shifting mechanism, there is necessary a period where power from an engine is disconnected while automatic shifting is performed by an actuator that shifts gears, so torque is decreased and the shifting ability is deteriorated resulting in, for example, a backward pulling effect of the vehicle when shifting.
Accordingly, a technology that includes an assist clutch for specific gear stages other than a main clutch has been proposed so that shifting is performed by alternately controlling torque of the main clutch and the assist clutch, thereby preventing disconnection during shifting by preventing torque drop that is generated during shifting (similar to double clutch shifting by a DCT).
However, in this transmission, torque assist is usually possible only from the first gear to the third gear, so a driver feels disconnection when shifting into higher gear stages.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.